Document singling arrangement

ABSTRACT

An arrangement for separately picking up documents, one by one, from a stack of documents located in a hopper, comprising an oscillatory arm for pre-separating the document to be picked up from the following one and a suction-type conveyor system for removing the document thus preseparated. The documents are removed periodically from the stack and follow each other at equal intervals. Both the oscillating arm and the suction conveyor system, when in motion, are periodically connected to the inlet port of vacuum pumping system in a duly timed manner.

D United States Patent 1 1 1111 3,885,784

Sautton May 27, 1975 [5 1 DOCUMENT SINGLING ARRANGEMENT 3,598,397 3/1971 Preisig 271/12 [75] Inventor: Guy Sautton, Paris, France Primary Examiner james B Marben [73] Assignee: Thomson-CS1, Paris, France Assistant Examiner-Bruce H. Stoner, Jr. [22] Filed: No 19, 1973 Attorney, Agent, or Firm-Cushman, Darby &

Cushman [211 App]. No.: 417,089

[57] ABSTRACT Fm'eigll Application i i y Data An arrangement for separately picking up documents, Jan. 27. 1971 France 71.02623 one by one, from a stack of documents located in a Sept. 14, 1973 France 73.33137 hopper, comprising an oscillatory arm for preseparating the document to be picked up from the fol- [52] US. Cl. 271/94; 271/30 A; 271/108 lowing one and a suction-type conveyor system for re- [51] Int. Cl B6511 3/08 moving the document thus preseparated. The docu- {58] Field of Search 271/11, 12, 13, 30 A, 30, ments are removed periodically from the stack and 271/93, 94, 95, 96, 90, 108, 196; 294/64 R follow each other at equal intervals. Both the oscillating arm and the suction conveyor system, when in mo- [56] References Cited tion, are periodically connected to the inlet port of UNITED STATES PATENTS vacuum pumping system in a duly timed manner.

1,853,781 4/1932 Rider 271/12 10 Claims, 13 Drawing Figures 2,761,680 9/1956 Lens 271/12 2,970,834 2/1961 Martin et a1. 271/96 3,154,306 10/1964 Elliott et a1. 294/64 R X HUENT 215127 10. 5 3,885 784 sum 3 DOCUMENT SINGLING ARRANGEMENT This is a continuation in part of application Ser. No. 2 l9,797 filed on Jan. 21, 1972 now abandoned.

The present invention relates to the separation of flat documents such as letters, cards, checks. etc., one by one and putting them in series at a determined interval or step. at a rate that can reach fifteen documents per second and even more, from a group of oriented documents, place to rest on one of their sides in a feeding device currently called a hopper.

There are now numerous known devices or mechanisms for performing such separations and putting in series and some of them resort to the action of a vacuum. One of these mechanisms. used for several years by the applicant, comprises mobile suction cups along a closed path and each intended, in turn, to take from the hopper the first document of the group of documents and leave it on a starting path where the documents are to follow in line at a determined interval.

In this known mechanism, the group of documents is acted on by mechanical means which press them in a given direction so as to place the first document to be separated in a vertical plane located in the axis of the starting path of the separated documents. Now, it has been found, in using this mechanism, that the following mishap occurs from time to time and in an erratic manner: the second document, which follows the first document picked up by a suction cup, leaves with this latter, which is reflected by a double pickup or, at least by a more or less considerable staggering of the second document in relation to the group of documents contained in the hopper, which results in creating an unevenness of the interval in the row of documents in series. This mishap is due to the fact that the documents, being in the hopper in a position of resting against one another, when the first document leaves with the corresponding suction cup, the elastic pressure which applies the second document against the first is reflected by a friction force. This latter is generally insufficient to assure carrying of the second document, but at times it is increased because of reliefs due to roughness such as poorly affixed postage stamps, poorly glued flaps, tears, folds, turned down corners, etc., presented by the documents. This friction force then at times becomes sufficient to cause the carrying along of the second document by the first with the resulting consequences, i.e., the necessary stopping of the processing line of the separation device.

The invention is intended to remedy this drawback. It has for its object an improved mechanism for separating documents, of the type with hopper and mobile elements for separation and carrying by suction, characterized in that it comprises in combination with the hopper and said separation and carrying elements, a preseparation device made, before the action of the mobile element, to move away the first document, to be separated from the rest ofthe documents in the hopper, and to hold it in pickup position by said element, away from the second document which follows it.

Consequently, all friction between the first and second document being eliminated, this second document is not carried by the suction cup when it carries the first document to separate it from the rest of the documents and engage it in the row of separated documents.

According to an embodiment, the preseparation device comprises an oscillating blade or similar piece, combined with mechanical means intended to make it oscillate in synchronsim with the movements of the suction cups, between a BACK position of resting against the grop of documents of the hopper and a FORWARD position of presentation of the first document in the plane of advancement of documents under the action of the suction cups. the movement of said blades being performed in about one hundredth of a second and at a rate of about 10 per second, said element comprising at least a suction orifice connected to a vacuum source, to carry with it, from the BACK position to the FORWARD position, the first document which is thus subjected to a strong acceleration having the effect of unsticking it from the following document.

But for said preseparation device to apply a strong acceleration, it is necessary that said document be solidly attached to the preseparation device. To increase the solidity of the attachment, the suction orifices connected to the vacuum source are multiplied. However, this device would be ineffective if, as a result of the unequalness of the size of the documents, deformation of one of them or for any other cause, a suction orifice were not blocked by a document. The flow of air through the orifice, in this case, would create an increase of the pressure in the vacuum supply of other orifices and would finally reduce thhe attachment of the document to the preseparation device.

According to another characteristic of this invention, the preseparation device is provided with several suction orifices distributed in at least two groups, each having an independent vacuum supply, whereby communication of one group with the atmosphere does not cause the vacuum to drop in the other groups.

Despite the use of this means for preseparation, double pickup may still occur.

Another purpose of the invention is to eliminate double pickups which may occur.

For this purpose, use is made of the fact that double pickups are less well attached than documents normally picked up: to eliminate double pickups, a strong acceleration is applied to the documents which makes the double pickups fall; they are then sent back to the hopper.

According to another characteristic of the invention, the documents picked up by the suction cups go along a path of advancement comprising a curve with slight radius whereby a centrifugal accleration of the order of ten times the acceleration of gravity is applied to the document.

The path followed by the documents fastened to the suction cup units is relatively long since, begun at the start of a rectilinear portion, it must comprise at least a curvilinear part. To increase the output of the apparatus, the space between two suction cups is reduced to a length less than said path: therefore, on the apparatus there are several units of suction cups under vacuum, each carrying its document. If for any reasons, a document should escape a unit of suction cups (or has not been picked up by the latter), the air intake thus created would run the risk, with the vacuum in the other suction cups falling, of reducing the solidity of the fastening of the documents by the other units. To limit this drawback, an arrangement is made so that at a maximum two units carrying suction cups are connected, at the same time, by a common piping to the vacuum source.

According to another characteristic of the invention. vacuum supply of the suction cups is made by sectors, each supplying two suction cups at a maximum.

Application of a centrifugal force makes it necessary that the documents picked up by the suction cups are well attached and resist this centrifugal force. Holding of the documents is improved by causing each one to be picked up by several suction cups. This arrangement further has the advantage of better holding large-size documents and prevents them from turning in a vertical plane around the axis of symmetry of the suction cup.

According to another characteristic of the invention, the suction cups are connected in units of at least two to pick up a document.

These suction cups which support the documents should follow their path and undergo considerable accelerations without vibrations harmful to the holding of the documents that they have picked up.

For this purpose, the suction cup units are connected to the chain at a point different from their center of gravity and are provided with feet intended to rest on the chain in its rectilinear path; when the unit is in the curvilinear part of the path, the centrifugal force applies to the suction cup unit a polarizing couple which eliminates play and prevents vibrations.

According to another characteristic of the invention, the suction cup unit is suspended at a point different from its center of gravity.

Mounting of the units is made in such a direction that the polarizing couple has a tendency to make the suction cup unit turn in the same direction as the rotation due to the pulleys; the suction cup unit is therefore oriented, when it is in the circular part of its path, in a position located in advance in relation to the orientation that it would have if it exactly followed the orientation that would be given to it by the element on which it is attached. Because of this fact, at the moment of reaching the plane of the document presented by the preseparation device, the suction cup unit is already stabilized in the position that it will occupy in the rectilinear part of its path.

According to another characteristic of the invention, the suction cup unit is suspended at such a point that the couple, which applies the centrifugal force to it, tends to make it turn in the same direction as the rotation which this centrifugal force has created.

But correct supply of all the suction cups is not yet sufficient to assure a sufficient solidity of the attachment of the documents by the suction cups. They still must have a shape and qualities which allow them to fulfill their role. Now, the work they must perform is different from that required of an ordinary suction cup which must be simply applied to a surface. Here the suction cups reach the surface they are to pick up at great speed tangentially; consequently, at each pickup of a document they slide against it. This feature requires a suction cup shape suitable both for supporting the sliding and reducing it to a minimum. In ordinary suction cups the edges of the lips are fine and flexible to achieve a good fluid tightness despite the unevenness of surface, while the body of the suction cups has a certain rigidity to assure stiffness when the pickup has been made. But in this type of suction cup, the edges of the lips would have a tendency to roll on themselves and would quickly be put out of service if they were used in the apparatus.

In the suction cups according to the invention, the function of fluid tightness is separated from the function of holding the picked up document. Fluid tightness is achieved by a circular toroidal bead intended to be applied to the surface of the document to be picked up. This bead easily supports the frictions to which it is subjected. It is connected to a central suction pipe by an extremely flexible membrane intended solely to assure fluid tightness. The holding is assured by a certain number of papillae attached in a relatively rigid way to the edges of the central supply pipe, the document resting firmly against these papillae by the vacuum created by the toroidal bead.

According to another characteristic of the invention, the suction cups are made up of a toroidal bead connected by a flexible membrane to the central supply pipe, a support surface, able to be made up of papillae, being made around the central supply pipe.

Experience has shown that it was difficult to achieve a correction presentation of documents in a facing position of the preseparation device with a horizontal hopper. On the other hand, a vertical hopper is more difficult to feed. It was found that a satisfactory functioning was obtained by giving the hopper an inclination of about 25in relation to the horizontal. But at the apparatus output, the documents must be presented vertically. This difficulty was resolved by inclining the suction cups in relation to their support at an angle approximately equal to half the angle of inclination of the hopper and by inclining, at the same angle and in the same direction, the device for moving the suction cups, made up of chain or the like moved by pulleys.

According to another characteristic of the invention, the hopper is inclined about 25on the horizontal, the suction cups being inclined at half the angle in relation to their support, and the device for moving the suction cups being inclined in the same direction of the same half angle.

Other characteristics will come out from the following description.

In the accompanying drawings, given solely by way of example:

FIG. 1 is a front elevation view of an improved mechanism according to the invention, the document hopper being shown in a very diagrammatic way;

FIG. 2 is a corresponding plane view;

FIG. 3 is a profile view along 3-3 of FIG. 1;

FIG. 4 is a front view of the preseparation element intended to separate the first document from the following documents of the group of documents contained in the hopper;

FIG. 5 is a vertical section along line 5-5 of FIG. 2, but on a larger scale, of the distributor that is part of the mechanism;

FIG. 6 is a plan view along line 6-6 of FIG. 5;

FIG. 7 is a similar view along line 7-7 of FIG. 5;

FIG. 8 is a view in partial section along line 88 of FIG. 7;

FIG. 9 is a side view of a unit carrying suction cups;

FIG. 10 is the cross section of this unit,

FIG. I1 is a front view of suction cup,

FIG. 12 is a section of a suction cup;

FIG. 13 is a time chart, giving, as a function of time t plotted as the abscissas, as I the successive portions of the mobile preseparation element, as II the successive putting under low pressure or at escape of the element and, as III the successive putting under low pressure and at escape of the units carrying the suction cups.

The known part of the mechanism will first be described.

It comprises a hopper M (FIG. 1, 2 and 3) provided with a support 1 with plane upper surface 2 slightly rising from back to front at an angle of about 25and on which a group of documents D is placed. The documents are in mutual contact by their large surfaces and rest by gravity on this surface 2; however, they are aligned on one of the vertical edges, the aligned edges being in contact with the vertical surface 3 directed from back to front, by a guide 4. The group of documents is thrust forward, in the direction of arrow f' (FIGS. 2 and 3) by a push rod 5, pulled by mechanical means not shown, because the hopper thus contituted is of the known type. Under the action of the mechani cal means thus assured, the group of documents D is moved so that the first document D is located in advancement plane V-V inclined in relation to the vertical about 25, whereby the successive documents should, one by one, be separated and placed in series at a constant interval or step, the documents leaving the mechanism in the direction of arrowj' (FIG. 2), this direction being horizontal and perpendicular to direction f' of the advance of the documents in hopper M,

A mechanical sensor 6 or photoelectric senser control the advance of the documents by means of known devices, schematized as 7. One by one separation of the documents is assured by suction cups driven, in a closed path on which portion ab (FIG. 2) is located in plane V-V of the advance of the documentsv This closed path comprises, in the example, two rectilinear portions ab and cd, connected by two half circumferences. This results from the fact that suction cups 8 are rigidly attached to units 9 carrying the suction cups (reference as 91, 92 depending on the position they occupy in the path), the cups are connected to an endless chain 10, these cup carrying units and the suction cups themselves will be described below in detail. This chain travels over two toothed wheels 11 and 12, whose axes WW and XX are inclined in the direction of hopper M at an angle of about I25, half the angle of inclination of said hopper. On these axes are the centers of two arcs of paths da and be respectively. Chain 10 moves on itself in the direction of arowf (FIG. 2), because toothed wheel 11 is driven in rotation in the direction of arrow f (FIG. 2) by a motor reduction gear 13 which drives shaft 14 on which this wheel 11 is keyed.

Each cup carrying unit 9 is connected by a flexible tube 15 to a distributor designated, in its entirety, as 16 and which will be described in greater detail below. This distributor makes it possible, in turn, to put each suction cup unit 9 in communication either with a low pressure source 17, or the atmosphere, in synchronization with the movement of chain 10, so that each suction cup unit is put in communication with the source a little before it reaches point a, and put on release a little before it clears point d and its path, part da of the path being accomplished with suction cup in communication with the atmosphere. The embodiment described here comprises four suction cup units but it is understood that it can have any number.

At the front of hopper M, beyond plane V---\/ of separation and advance of the documents, is placed a preseparation element 18, made up of a blade having, preferably, the shape of the letter F (see FIG. 4), in the sense that is presents two parallel active branches 19 and a lengthwise portion 20, terminated by an eye 21 for connection around a journal 22 whose axis YY is located practically in the vertical plane of pickup and advance.

This element I8 can oscillate around axis Y)( between two positions, one front, represented by 18" in solid lines on FIG. 3 and the other, back, shown as 18 in mixed lines. Position 18 is such that a document D" resting against its back face, is exactly in plane V-V of separation and advance.

The oscillation movements are imparted to element 18, from shaft 14 (FIG. 2), by cam 23 keyed on this shaft and against which a roller, as a countercam 24, is held and rests. This roller is carried by a lever 25, mounted to oscillate around a shaft carried by the frame. The lever is connected by a link 27 to element 18, this link being connected to a strap 28, rigidly attached to this element. A spring 29 keeps roller 24 resting on cam 23 which consequently tends to recall element 18 to back position 18'- Cam 23 has the number of bosses necessary for each of them to bring element 18 into position 18' each time a suction cup carrying unit is in the pickup position.

In particular there will be noted curve 26 of the bosses of cam 23 which is an important characteristic of the invention. There is called a curve or slope of a cam profile at a point the angle made by the tangent to this profile with the perpendicular to the radius. This curve whose average slope here is about 45has the effect of giving lever 25 a sudden movement as will be ex plained below.

Preseparation element 18 is intended to act on first document D to unstick it from the other documents and, in particular, from second document D and to carry it with it in plane V-V. For this purpose, it comprises suction orifices distributed in two groups 30 and 301 which come out into independent ducts 31 and 311 in communication by two flexible conduits 32 and 321 with distributor 16 which will now be described with reference to FIGS. 1 and 2 and 5 to 8.

This distributor comprises a shaft 33, with axis Z-Z parallel to axes WW and X-X and located in the same plane as them. It was seen that this plane formed an angle of about I2.5with the vertical plane. This shaft pivots in frame 34 (FIG. 1) by means of a bearing not shown and it comprises, between a shouldering washer 35 (FIG. 5) and a lock nut 36, a downward pile of four disks 37, 38, 39 and 40. Upper and lower disks 37 and 40 are keyed on bearings 41 and 42 of the shaft and turn with it around axis ZZ, while the two intermediate disks 38 and 39 are to slide on a central bearing 43 of the shaft, but are prevented from turning by fixed pins 44, these pins being engaged in notches 45 and 46 of these disks 38 and 39. They are separated axially by a spring 47 (FIG. 5) which is housed around bearing 43 in counterbores opposite the two disks and which tend to apply them, in a fluid-tight fashion, on the opposite faces of disks 37 and 40. These disks 37 and 40 which, with shaft 33, form a rotating unit, are driven in rotation in synchronism with chain 10 carry ing the suction cup because one of these disks, for example, upper disk 37, comprises on its periphery a gearing 48, thanks to which, the toothed wheel this constituted is driven in rotation by shaft 14 which carries toothed wheel 11, with the aid of a transmission chain 49 or a notched belt (FIG. 1 and 2) and a driving pinion 50, keyed on shaft 14. The transmission ratio is such that shaft 33 and two disks 37 and 40 of distributor 16 make a revolution per revolution of chain on itself.

Disks 37 and 38 work together to assure putting under low pressure and a release, i.e., in communication with the atmosphere, of each of the suction cup units of the device, and according to graph III of the time chart of FIG. 13 so that at time r i.e., very close to the moment when preseparation element 18 begins to advance, a first suction cup unit 91 is put under low pressure, slightly before this unit reaches point a (FIG. 2). This suction cup unit 91 remains under vacuum during the time of its path abcd where it is put back in communication with the atmosphere, the picked up document at that moment being taken by another device not shown. But suction cup unit 92 following group 91 reaches pickup position a before group 91 has reached d. For reasons set forth above, the vacuum in unit 91 must be independent of the vacuum in following groups 92 and 93, etc. Therefore, particular vacuum supplies must be provided to each suction cup unit that presents itself in the pickup position.

This result is achieved by the arrangement shown in FIGS. 5 and 6. Four flexible tubes 15, each connected to a suction cup unit, come out on four nozzles such as nozzle 51 of FIG. 5 and each of these nozzles is extended in disk 37 by a hole 52, 53, 54 or 55 (FIG. 6). These holes come out on the lower face of disk 37 and are intended, in turn, during rotation of upper disk 37 in the direction of arrow f (FIG. 6), to pass first on a cruved groove 56, made in stationary disk 38, then on a second curved groove 561 and finally on a third shorter curved groove 57 made in the same disk. lnto grooves 56 and 561 there come out two nozzles 58 and 581 connected, by two conduits S9 and 591, to low pressure source 17, while the other groove 57 is at release at 60. As can be seen in FIG. 6, the space that separates grooves 56 and 561 is slighter than the diameter of holes 52, 53, 54 and 55. In this way, when one of these holes goes from grooves 56 to groove 561, it is always in communication with the vacuum source by putting grooves 56 and 561 in communication with one another for a very short time.

As can be seen, considering the rotation along arrow P of mobile disk 37 of the distributor, each suction cup unit is in communication with the low pressure source, while the corresponding hole, such as 52 is above grooves 56 and 561, while it is at release when said hole is above groove 57.

In regard to the distribution pertaining to preseparation element 18, this distribution is assured by the combination of lower disks 39 and 40 (see FIGS. 5, 7 and 8). Disk 39, which is fixed in rotation, comprises, side by side (see FIG. 7), two double nozzles 61, 611, 62, 621, on which are connected, respectively, tubes 63, 631 connecting distributor 16 to low pressure source 17 and tubes 32, 321 which come out at preseparation element 18.

To each nozzle 61, 611, and 62, 621 there correspond, in disk 39, recessed holes 64, 641 or 65, 651 which come out downward on the upper face of lower disk 40 (in particular see FIG. 8) and these holes can, during the desired periods of putting under low pressure of preseparation element 18, be connected to the low pressure source by nozzles 61, 611 and tubes 63, 631, thanks to one of four curved grooves 66, made in the upper part of lower disk 40. Each of these grooves is arranged so that during a given cycle, the two groups of suction orifices of the preseparation element are put under low pressure before said element has begun its movement toward the FORWARD position to the moment when, being in the FORWARD position, a suction cup unit presents itself. Putting of element 18 under release is assured by holes 67 for connecting with the outside air, made in lower rotating disk 40 and which will coincide with holes 65 and 651. Meantime, holes 67 will pass for a very brief instant under holes 64 and 641 and will put source 17 at release, but for such a short time that the loss of vacuum will be negligible.

It will be noted that the period of putting element 18 under release is sufficient for this element not to risk disturbing the start of document D carried by the suction cup because, during all this time, this element 18 remains in its FORWARD position against this document D" its return to the BACK position occurring only in the following period.

FIGS. 9 and 10 represent a suction cup carrying unit in a side view and in cross section. It is made up of a machined or cast unit comprising a body 70 in which two holes 71 have been drilled for the axes of the chain links to pass through, the distance between these two holes being approximately equal to the length of a link. On this reinforcement is hollowed a nozzle 72 approximately parallel to the axis of holes 71 which is intended to be connected by a flexible tube to distributor 33. This nozzle 72 is in communication with two nipples 73, intended to receive the suction cups which will be described below. It should be noted that the axis of these two nipples is inclined in relation to the axis of holes 71 by an angle 1' approximately equal to half the angle by which hopper M is inclined, i.e., about 12.5". On the other side of these nipples 73, in relation to reinforcement 70, is located a flange 74 intended to guide unit 9. For this purpose, two wedges and 76 are attached respectively on the flange and on the back part of the nipples and are intended to rest on the chain in its rectilinear travel. Unit 9 is made so that the mass of the part where nipples 73 are located is greater than that of flange 74; in this way, in the circular portions of the path, the centrifugal force applies a couple directed along the axis of holes 71 to unit 9 and tends to apply flange 74 toward the center of rotation.

It can be seen that by this arrangement, unit 9 is always held either on the rectilinear path by wedges 75 and 76 in contact with the chain or in the curvilinear path by the rotation couple whose effect is always to take up the play of axes 71 in the same direction. Further, arrangements are made so that this couple, due to the centrifugal force, is directed in the same direction as the rotation of pulleys 11 and 12. Because of this fact, at the end of the curvilinear path, i.e., at the moment when the suction cups come in contact with the first document to be picked up, unit 9 has an orientation ahead of that it will occupy during its rectilinear path. Wedge 75 will come in contact with the chain before wedge 76. In other words, unit 9 ends its curvilinear path by its translation along a curve which joins with the rectilinear path and thereby the suction cups, while remaining parallel to themselves, tangentially approach the first document that is to be picked up. Unit 9 acts like a sort of flail which would whip the first document.

The presence of two suction cups has the additional advantages. besides a general improvement in the solidity of the pickup of the documents, of preventing them from turning around a horizontal axis, as sometimes occurs in a device with a single suction cup when the document has been picked up far from its center of gravity.

The suction cups which are applied on the nipples 73 are described in FIGS. 11 and 12. They are made up of an approximately toroidal ring 77 connected to base 78 of the suction cups by a fluid tightness cover 79 of great flexibility and whose thickness is very slight, of the order of one-third millimeter. Contact papillae 80 are distributed around orifice 81, being applied on nipples 73. They are of elastic material and intended to be applied by the vacuum on the document on which they are supposed to be fastened.

It can be seen that in this type of suction cup, the functions of fluid tightness, performed by the toroidal ring and cover are independent of the attachment functions performed by the papillae firmly resting on the document to be attached. This has the advantage of causing an improved holding of the document and especially of considerably reducing the friction wear of the suction cups in comparison with those of the prior art whose lips had a tendency to roll against the document at the time of pickup, thus causing, besides a poor pickup, a rapid wear of the suction cups.

Functioning of the apparatus will be explained by using the graphs of FIG. 13.

It is assumed that the apparatus comprises four suction cup carries but it is understood that it could have a different number. These suction cup carries are numbered 91, 92, 93, 94, taking them in the order of ad vancement, the first that which is in the pickup position opposite preseparator 18.

On the graph of FIG. 13, the times are shown as abscissas and the various families of curves as the ordinates.

Curve I refers to the position of preseparator 18: the high parts of the curve indicate the instants when the preseparator is in the FORWARD position, which corresponds to the presentation of the first document at pickup by the suction cup carrier.

Curve II indicates putting ducts 32 and 321 of preseparation element 18 in communication with the vacuum source. The high position of the curve corresponds to putting under vacuum, while the low position indicates putting in communication with the atmosphere.

Curves III concern the suction cup units. The high position corresponds to putting under vacuum, in solid lines putting under vacuum is achieved by curved groove 56 (FIG. 6), while the dotted line indicates putting under vacuum by groove 561. The low position corresponds to putting in communication with the atmosphere.

The absence of a line on any of the curves indicates that considered is neither under vacuum nor in communication with the atmosphere.

There has been chosen as the origin of times (r the instant when preseparation element 18 is put under vacuum, curved grooves 66 (FIG. 7) placing themselves under orifices 65 and 651. At this instant, preseparation element 18 is in the BACK position (18, FIG. 3) and presses the documents piled in hopper M.

Suction cup unit 9], the first to present itself in pickup position, is still in the curvilinear portion do of the path.

From 1 to r the preseparation element makes its rapid movement to FORWARD position, carrying the first document by suction. This movement lasts about one hundredth of a second, thanks to the curve of cam 23 (FIG. 2) and this is an important characteristic of the invention the second document, still applied against the first by the force exerted by push rod 5 (FIG. 2 and 3), does not have time to move to follow the first document. The separation of documents therefore is performed by inertia, the first document being, so to speak, torn" from the pile of documents in the hopper.

At instant t putting of suction cup carrier 9] under vacuum is also performed, the latter approaching the plane of advance of documents VV parallel to itself.

At the moment of contact of suction cup carrier 91 with the first document at instant I the preseparator element is put in communication with the atmosphere until r and does not oppose the advance of the first document along path ab.

From I to 1 the preseparator element comes back to BACK position pressing the pile of documents in hopper M.

At r said preseparation element is again put in communication with the vacuum source to perform the separation of the following document. At this moment, supply of vacuum to the suction cup carrier 91 is no longer performed by curved groove 56 but by curved groove 561 for reasons set forth above (dotted line).

The same process takes place for the preseparation element and suction cup carrier 92 and for suction cup carrier 91.

From to I sue-tion cup carrier 91 describes the element of path be around pulley 12: during this time it is subjected to an centrifugal acceleration of the order of 20,000 cm given the radius of the pulley (l2 cm) the height of the suction cup carrier (6 cm) and the traveling speed of the chain (4 meters per second) or about 20 times the acceleration of gravity. As said above, double pickups, having a less good hold than normal pickups, are ejected during this part of path be.

At 1 the preseparation element is again put under vacuum to perpare for the pickup of a new document by suction cup carrier 93, while vacuum supply of suction cup carrier 92 is transferred from groove 56 to groove 561 (FIG. 6).

At 1. at the instant when the preseparation element is again put under vacuum for a fourth separation of the document intended for suction cup carrier 94, suction cup carrier 91 is put in communication with the atmosphere until 1 At this moment suction cup carrier 91 is close to point d and the document that it carriers is taken by another mechanism that is not part of the invention.

The cycle is followed for the other suction cup carriers. Arriving at time t corresponding to time I of the preceding cycle, suction cup carrier 92 having reached point d gives up its document, being in com munication with the atmosphere to r corresponding to time In I claim:

1. Mechanism to assure the one by one separation and the putting in series at a constant interval of documents from a stack of documents, comprising:

a hopper that contains this stack of documents and presents them to be picked up.

a preseparation element intended to separate the first document from the rest of the documents in said hopper and hold it in the pickup position,

mobile suction means to pick up the first document presenting itself in pickup position and to make it advance to the end of the advancement path, said suction means comprising:

conveyor means to which are attached a plurality of evenly spaced suction cup carrier units,

at least two pulleys on which said conveyor means travels, the documents being conveyed around the are of at least one of the pulleys, said pulleys having shafts whereof one is driven by motor means, and

a distributor to supply a vacuum to the suction cup carrier units, said distributor being connected to the vacuum source by two distinct conducts, one of which is used to supply a vacuum to the suction cup carrier units presenting themselves in the pickup position and the other is used to supply a vacuum to the suction cup carrier units starting from a position located between the pickup position and the passage around the pulley to the position of the end of the path, said distributor further connecting said suction cup carrier units to atmospheric pressure when they reach said end of path position.

2. Mechanism as claimed in claim 1, wherein said preseparation element is placed between said hopper and said mobile suction means and is made up of a lever, reciprocably oscillating between a REARWARD position resting on the documents contained in said hopper and a FORWARD position corresponding to the position for picking up said document by said mo bile suction means, said oscillating lever being provided with a plurality suction orifices facing said documents in said hopper and successively put in communication with a vacuum source and the atmosphere and being mechanically coupled to a roller rolling on a cam secured to and rotating with said shaft of one of said pulleys, said cam having an outer face so arranged that said oscillating movement is performed rapidly in about a hundredth ofa second and the first document applied by the vacuum on said oscillating lever is torn from the following document and presented separately in pickup position to said mobile suction means.

3. Mechanism as claimed in claim 2, wherein said suction orifices of said oscillating lever include two distinct groups each having an independent vacuum conduit, whereby putting of one group in communication with the atmosphere does not make the vacuum drop in the other group.

4. Mechanism as claimed in claim 1, wherein each suction cup carrier unit includes at least two suction cups,

5. Mechanism as claimed in claim 1, wherein said suction cup carrier unit is carried by said conveyor means at a point offset from its center of gravity, whereby the centrifugal force applies a polarizing couple to the unit during the curvilinear parts of the path.

6. Mechanism to assure the one by one separation and the putting in series at a constant interval of documents from a stack of documents, comprising:

a hopper that contains this stack of documents and presents them to be picked up, said hopper being inclined on the horizontal at an angle of about 25 degrees so that the documents are supported at substantially the same angle relatively to the vertical and are obliged to ascend to reach the pick-up position,

a prese'paration element intended to separate the first document from the rest of the documents in said hopper and hold it in a pickup position, said pickup position being inclined in relation to the vertical at an angle corresponding approximately to the angle of inclination of the hopper on the horizontal,

mobile suction means to pick up the first document presenting itself in the pickup position and to make it advance to the end of an advancement path. said suction means comprising:

conveyor means to which are attached a plurality of evenly spaced suction cup carrier units for carrying suction cups inclined in relation to the attachment of the suction cup carrier unit on the conveyor means by an angle equivalent approximately to half the angle by which the hopper is inclined on the horizontal.

at least two pulleys on which said conveyor means travels, said pulleys having shafts whose respective axes are inclined in relation to the vertical at an angle approximately equal to half of the angle by which the hopper is inclined in relation to the horizontal, whereby the documents, picked up at the outlet of the hopper with a certain angle in relation to the vertical, are vertical at the end of the path.

7. Mechanism as claimed in claim 6, wherein said preseparation element is placed between said hopper and said mobile suction means and is made up of a lever, reciprocably oscillating between a REARWARD position resting on the documents contained in said hopper and a FORWARD position corresponding to the position for picking up said document by said mobile suction means, said oscillating lever being provided with a plurality suction orifices facing said documents in said hopper and successively put in communication with a vacuum source and the atmosphere and being mechanically coupled to a roller rolling on a cam secured to and rotating with said shaft of one of said pulleys, said cam having an outer face so arranged that said oscillating movement is performed rapidly in about a hundreth of a second and the first document applied by the vacuum on said oscillating lever is turn from the following document and presented separately in pickup position to said mobile suction means.

8. Mechanism as claimed in claim 7, wherein said suction orifices of said oscillating lever include two distinct groups each having an independent vacuum conduit whereby putting of one group in communication with the atmosphere does not make the vacuum drop in the other group.

9. Mechanism as claimed in claim 6, wherein each suction cup carrier unit includes at least two suction cups.

l0. Mechanism as claimed in claim 6, wherein said suction cup carrier unit is carried by said conveyor means at a point offset from its center of gravity, whereby the centrifugal force applies a polarizing couple to the unit during the curvilinear parts of the path. k 

1. Mechanism to assure the one by one separation and the putting in series at a constant interval of documents from a stack of documents, comprising: a hopper that contains this stack of documents and presents them to be picked up, a preseparation element intended to separate the first document from the rest of the documents in said hopper and hold it in the pickup position, mobile suction means to pick up the first document presenting itself in pickup position and to make it advance to the end of the advancement path, said suction means comprising: conveyor means to which are attached a plurality of evenly spaced suction cup carrier units, at least two pulleys on which said conveyor means travels, the documents being conveyed around the arc of at least one of the pulleys, said pulleys having shafts whereof one is driven by motor means, and a distributor to supply a vacuum to the suction cup carrier units, said distributor being connected to the vacuum source by two distinct conducts, one of which is used to supply a vacuum to the suction cup carrier units presenting themselves in the pickup position and the other is used to supply a vacuum to the suction cup carrier units starting from a position located between the pickup position and the passage around the pulley to the position of the end of the path, said distributor further connecting said suction cup carrier units to atmospheric pressure when they reach said end of path position.
 2. Mechanism as claimed in claim 1, wherein said preseparation element is placed between said hopper and said mobile suction means and is made up of a lever, reciprocably oscillating between a REARWARD position resting on the documents contained in said hopper and a FORWARD position corresponding to the position for picking up said document by said mobile suction means, said oscillating lever being provided with a plurality suction orifices facing said documents in said hopper and successively put in communication with a vacuum source and the atmosphere and being mechanically coupled to a roller rolling on a cam secured to and rotating with said shaft of one of said pulleys, said cam having an outer face so arranged that said oscillating movement is performed rapidly in about a hundredth of a second and the first document applied by the vacuum on said oscillating lever is torn from the following document and presented separately in pickup position to said mobile suction means.
 3. Mechanism as claimed in claim 2, wherein said suction orifices of said oscillating lever include two distinct groups each having an independent vacuum conduit, whereby putting of one group in communication with the atmosphere does not make the vacuum drop in the other group.
 4. Mechanism as claimed in claim 1, wherein each suction cup carrier unit includes at least two suction cups.
 5. Mechanism as claimed in claim 1, wherein said suction cup carrier unit is carried by said conveyor means at a point offset from its center of gravity, whereby the centrifugal force applies a polarizing couple to the unit during the curvilinear parts of the path.
 6. Mechanism to assure the one by one separation and the putting in series at a constant interval of documents from a stack of documents, comprising: a hopper that contains this stack of documents and presents them to be picked up, said hopper being inclined on the horizontal at an angle of about 25 degrees so that the documents are supported at substantially the same angle relatively to the vertical and are obliged to ascend to reach the pick-up position, a preseparation element intended to separate the first document from the rest of the documents in said hopper and hold it in a pickup position, said pickup position being inclined in relation to the vertical at an angle corresponding approximately to the angle of inclination of the hopper on the horizontal, mobile suction means to pick up the first document presenting itself in the pickup position and to make it advance to the end of an advancement path, said suction means comprising: conveyor means to which are attached a plurality of evenly spaced suCtion cup carrier units for carrying suction cups inclined in relation to the attachment of the suction cup carrier unit on the conveyor means by an angle equivalent approximately to half the angle by which the hopper is inclined on the horizontal. at least two pulleys on which said conveyor means travels, said pulleys having shafts whose respective axes are inclined in relation to the vertical at an angle approximately equal to half of the angle by which the hopper is inclined in relation to the horizontal, whereby the documents, picked up at the outlet of the hopper with a certain angle in relation to the vertical, are vertical at the end of the path.
 7. Mechanism as claimed in claim 6, wherein said preseparation element is placed between said hopper and said mobile suction means and is made up of a lever, reciprocably oscillating between a REARWARD position resting on the documents contained in said hopper and a FORWARD position corresponding to the position for picking up said document by said mobile suction means, said oscillating lever being provided with a plurality suction orifices facing said documents in said hopper and successively put in communication with a vacuum source and the atmosphere and being mechanically coupled to a roller rolling on a cam secured to and rotating with said shaft of one of said pulleys, said cam having an outer face so arranged that said oscillating movement is performed rapidly in about a hundreth of a second and the first document applied by the vacuum on said oscillating lever is turn from the following document and presented separately in pickup position to said mobile suction means.
 8. Mechanism as claimed in claim 7, wherein said suction orifices of said oscillating lever include two distinct groups each having an independent vacuum conduit whereby putting of one group in communication with the atmosphere does not make the vacuum drop in the other group.
 9. Mechanism as claimed in claim 6, wherein each suction cup carrier unit includes at least two suction cups.
 10. Mechanism as claimed in claim 6, wherein said suction cup carrier unit is carried by said conveyor means at a point offset from its center of gravity, whereby the centrifugal force applies a polarizing couple to the unit during the curvilinear parts of the path. 